NL8601182A - METHOD AND DEVICE FOR RECORDING AND / OR PLAYING AN IMAGE SIGNAL AND AN ASSOCIATED AUDIO SIGNAL IN RESPECT OF A REGISTRATION CARRIER, AND OBTAINING A REGISTRATION CARRIER BY THE METHOD - Google Patents

Description

- PHN 11,753 1 N.V. Philips' Incandescent light factories in Eindhoven.

Method and device for recording and / or reproducing an image signal and an associated audio signal in a record carrier, respectively, and a record carrier obtained according to the method.

The invention relates to a method for recording and / or reproducing an image signal and an associated audio signal in a record carrier, respectively, wherein during recording the image signal and the audio signal are encoded into a first and a second information signal, respectively, containing information words are packaged (frames), each packet is provided with a packet header (header) and a data field, in which a data field of a packet contains a number of information words of the image signal or the audio signal, the packet header indicates the information signal to which the information words in the data field, after which the packets are registered on the record carrier; and wherein during playback the packets are read from the record carrier and decoded to obtain the image signal and the associated audio signal. The invention also relates to an apparatus for carrying out the method and to a record carrier obtained according to the method. The method of the type mentioned in the opening paragraph is described in the previously filed Dutch patent application no.

8,600,450 (PHQ 86,003), also from applicant. More particularly, the invention relates to a method for recording and reproducing image signals and associated audio signals in the form of digital information in a record carrier, such as, for example, a compact disc.

As is generally known, the compact disc is a record carrier for storing digital information, which record carrier can contain a certain number of bits. The first application of the compact disc in the Compact Disc Digital Audio system is several years old and provided for use as a record carrier for 16-bit PCM encoded audio signals. For a very complete description of this system, reference is made to Philips' technical magazine Vol. 40, 1982, no. 6, in particular the article therein by J.P.J. Heemskerk et al entitled "Compact disc: 3601182 ΡΗΝ 11,753 2 i * i system aspects and modulation", pages 157 to 164.

A second application provided for use as a data ROM for data processing equipment. A third application is currently under development and provides for use as a record carrier for 5 digitized video signals of images accompanied by digitized audio and possibly computer data.

This currently envisaged application of the compact disc is an interactive application, referred to as CD-I. Lectures about this new application were already given at the 10th Microsoft Conference in Seattle, March 3-5, 1986, a lecture by D.C. Geest entitled "Standardization of CD-I" and a lecture by R.

Bruno with the title "New developments in optical media", and was published in the Philips Courier of March 13, 1986, p. 1 and 2.

In order to be able to record an image on a record carrier in the form of a compact disc, the image is divided into a number of lines (for example 280 pieces) and each line is again divided into a number of contiguous picture elements (for example 384 pieces). It is hereby assumed that each picture element has a uniform brightness and a uniform color. An image element is now fully described by a number of image components; namely the brightness component Y (i, k) and the two color difference components ü (i, k) and V (i, k), or which amounts to the same thing by the three basic color components R (i, k), G (i, k) and B (i, k). Here i indicates the rank number of the line and k the rank number of the picture element on this line (column).

Each of the picture components of a picture element is subjected to encoding, so that for each picture element an information word is obtained, which will be mentioned in the following video word. When PCM encoding is used, the 30 picture components of each picture element are encoded separately; that is, independently of corresponding picture components from other picture elements. However, if the picture components are subjected to a DPCM encoding, the difference between the corresponding picture components of two consecutive picture elements in each case is roughly the difference subjected to a PCM coding. Since the encoding of such a difference generally requires fewer bits than the encoding of each of the individual picture components, the new application of the compact disc 4-bit DPCM encoding is used for the planned 8601182 * * «« PHN 11.753 3 of the image components. This means that each picture element is characterized by a 12-bit video word.

In order to utilize the capacity of the record carrier as economically as possible, the entire block of 280 x 384 video words is transferred only once. The monitor has an image memory that contains at least as many memory locations as the image picture elements. A picture element is uniquely associated with each memory location and such a memory location contains the transmitted video word of the relevant picture element. This image memory is read repeatedly in the usual manner in order to obtain the relevant image on the display.

It should be noted that in practice it does not appear to be necessary to transfer both the brightness component and the two color difference components of each picture element. It has been found to be sufficient to transmit the brightness component of each picture element and the color difference component ü and the color difference component V alternately from successive picture elements. This means that each picture element can be characterized by a 3-bit video word. More specifically, the first four bits of this video word represent the brightness component of the picture element in DPCM format and the other four bits represent one of the two (alternating) color difference components, also in DPCM format. In the following, the entirety of video words to be transmitted, which together define a certain image, will be referred to as video block.

In the currently envisaged new application of the compact disc, like the digitized information elements, sound and computer data, a video block is packaged before recording on the record carrier. In addition, each packet 30 includes, for example, 2352 bytes and each packet is broadly divided into two fields; namely in a packet header consisting of 24 bytes and a data field of '2328 bytes. The last 280 bytes in the data field can possibly be used for error protection and correction of the other bytes in the data field. This is used, for example, if the package contains computer data.

The packet header includes synchronization bytes for byte and bit synchronization, but also indicates whether the data in the s o o i *: c; , l * PHN 11.753 4 data field is image information or audio or computer data. In these cases we speak of a video package, an audio package and a computer data package, respectively. The data field of an audio packet contains 1164 audio words of 16 bits each, while the data field of a video packet contains 2328 video words of 8 bits each.

The new application of the compact disc which is currently envisaged also provides the possibility of choosing between a number of different qualities for the audio signal.

- First, there is the quality known from the original application in the Compact 10 Disc Digital Audio system. From a compact disc completely filled with audio signals, it is possible to obtain about 72 minutes of stereo sound with the quality known from the compact disc (90 dB or more dynamics).

- Second, there is the "hi-fi music" mode. This capability provides two stereo channels readable in parallel or four mono channels readable in parallel. On a full compact disc there is again about 72 minutes of sound per stereo channel. So if only one mono signal is to be recorded on a compact disc, you can record 4 x 72 minutes audio signal on a complete compact disc.

20 The quality corresponds to that of a LP.

- Thirdly, there is the so-called "midfi music" mode. Here, on a full compact disc, there are four parallel channels with a stereo signal of 72 minutes long in each channel, or eight channels with a mono signal of 72 minutes long. The quality corresponds to that of an FM

25 radio broadcast.

- Fourth, there is the "speech" mode. This capability provides 8 parallel channels with stereo or 16 parallel channels with up to 72 minutes of mono signal on a full compact disc. The quality is that of an AM radio broadcast.

30 is CD digital audio, as is known in 16 bit PCM

encoded and the full storage capacity of the compact disc is required to store the 72-minute stereo signal.

For the three other qualities with which the audio signal can be recorded on the record carrier, this is realized by means of an 8- or 4-bit ADPCM (adaptive data pulse code modulation).

With these three options, a storage capacity of 3101182 s 4 PHN 11.753 5 50%, 25% and 12.5% is required to store the audio information of one channel, respectively. The rest of the storage capacity is then available for storing video information, computer data or other sound channels. In the latter case, one has the option of storing 5 narration in different languages in a corresponding number of parallel channels.

- A fifth possibility is to encode spoken text phonetically so that a much longer playing time can be realized. The standard phonetic alphabet, as specified for the desired language, or languages, is encoded and recorded on the compact disc along with a set of diphones for the desired language and a resynthesis program, using which the spoken text is read by coupling diphones together can resynthesize. The resulting information density in one channel can be very high and can provide a playing time of more than 5000 hours for a 15 full compact disc.

In those cases where one has two or more parallel, as mentioned before, it is possible to store the same spoken text in these channels but translated in different languages on the compact disc. This is particularly important when simultaneously displaying image information and associated narration, whereby one has the option of a certain language in which the narration is displayed.

The invention now aims to indicate measures which make it possible to display image information together with one associated audio signal, selected from different audio signals associated with the image information, of the record carrier. In the case of an audio signal, one should think here for example of a piece of text belonging to the image information (the image), which is spoken in a certain language. This picture information includes other audio signals, namely the same text but pronounced in a different language (other languages). To that end, the method is characterized in that, for recording at least a second audio signal associated with the image signal, the second audio signal is encoded into a third information signal containing information words which are accommodated in packets, which are included in the packet header of those packets which audio signal additionally indicates to which of the two or more audio signals the information words in a data field of a packet ^ 'Λ Λ rt Λ ODJ i I' J L.

PHN 11,753 6 further include that reference signals and additional packets are recorded in the record carrier, which additional packets for each of the two or more audio signals associated with an image signal contain time information about the length of time between the occurrence of a reference signal after the read out and the moment when a read-out image signal must be made visible on a screen, and during playback the reference signals and the additional packets are read out from the record carrier, under the influence of a first control signal, the time information associated with one of the audio signals from a additional packet is derived and then a second control signal is derived from the thus derived time information and a detected reference signal for displaying an read-out image signal on a screen, and that under the influence of the first control signal only the one aforementioned audio signal is is displayed.

The invention is based on the insight that, given that one language is more distinct in composition than the other, the moment of displaying an image associated with a text pronounced in a certain language will take place at a different time than in case the text would be shown in a different language. The record carrier must therefore contain information for each language regarding the times at which subsequent images are to be displayed during a text spoken in a certain language. This information is in the form of the time lapse between the moment of occurrence of a reference signal in the information read out from the record carrier and the moment of displaying an image. This time course will therefore generally be different for the different audio signals (languages). For example, a reference signal can be stored in the packet header (eg, the subheader) of an additional packet. Another possibility is to store an associated reference signal for each audio signal (each language) in the packet header (for example the subheader) of the first packet following the additional packet, which contains information words of the conscious audio signal in its data field.

The time information can be included in the data field of an additional package. These additional packages are already present on the record carrier anyway and contain the software 86 011S 2 *. * PHN 11.753 7 which must be read out and stored in the processor of the reading device and which enables the correct functioning of this device .

The device for recording an image signal and an associated audio signal, for carrying out the method, comprising - a first input terminal for receiving the image signal, - a second input terminal for receiving the audio signal, - an encoding unit with a first and a second input coupled to the first and second input terminal and an output terminal, respectively, which encoding unit is adapted to encode the image signal and the audio signal into the first and second information signal, respectively, in the form of successive information words. accommodating the information words in packets (frames), is arranged for accommodating a signal code in the packet header indicating the information signal to which the information words belong in the data field of the associated packet, and is arranged for supplying successive packets to its exit, - an enrollment unit, with an entry ng coupled to the output of the encoding unit, which writing unit is arranged for writing the consecutive packets into the record carrier, characterized in that the coding unit is arranged for encoding at least a second audio signal associated with the picture signal a third information signal, in the form of consecutive information words, is arranged to accommodate these information words in packets, is arranged to accommodate a signal code in the packet header of packets containing an encoded audio signal, indicating to which of the two or more audio signals include the information words in the data fields of these packets, that the encoder includes a reference signal generator for supplying reference signals, that the unit is further arranged to generate additional packets, which additional packets for each of the two or more 35 aud. associated with an image signal iosignals contain said time information, and is arranged to supply these additional packets to its output terminal.

Such a device can be further characterized in that the 3501132, i * PHN 11.753 8 encoder contains - an audio encoder for encoding an audio signal, with an input coupled to the second input terminal, and an output, - a video encoder for encoding a image signal, with an input coupled to the first input terminal, and an output, - a signal combining unit with a first, a second and a third input coupled to the outputs of the audio encoder and the video encoder and the reference signal generator, respectively, and an output coupled to the 10 output terminal, that the encoder further comprises a third input terminal for receiving said time information, which third input terminal is coupled to a fourth input of the signal combination unit, and that the signal combination unit is arranged for storing the information words of the audio encoder and the video encoder in the data fields of packets, is arranged to accommodate the signal code in the packet header of packets, and is arranged to store the time information in the additional packets.

The device for reproducing an image signal and an associated audio signal, for carrying out the method, comprising - a reading unit, for reading successive packets from the record carrier and for supplying these packets to an output, - a decoding unit with an input coupled to the output of the reading unit, and a first and second output, which decoding unit is arranged for separating packets containing information words from the first information signal and packets containing information words from the second information signal, is arranged for decoding the first and the second information signal into the image signal and the audio signal, respectively, and is arranged to supply these signals to a first and second output terminal, respectively, characterized in that the decoding unit comprises a control input for receiving the first control signal , and that the decoders It is adapted to derive one of the 8601182 r * PHN 11.753 9 two or more audio signals under the influence of the first control signal and to supply this audio signal to its second output terminal, which decoder is further arranged to separate the reference signals and the additional packets of the information read from the record carrier, for deriving the time information associated with the conscious audio signal under the influence of the first control signal, for deriving the second control signal, and for supplying the image signal to its first output terminal under the influence of this second control signal.

Such a device may further be characterized in that the encoding unit comprises a signal separating unit, an audio decoding unit, a video decoding unit, a control unit and a clock signal generator, the input terminal of which is coupled to an input of the signal separating unit, a first, a second and a third output 15 of which is coupled to inputs of the video decoding unit and the audio decoding unit and a first input of the control unit, respectively, outputs of the video decoding unit and the audio decoding unit are coupled to the first and second output terminals, respectively, an output of the clock signal generator is coupled to a second input of the control unit, an output of which is coupled to a control input of the video decoding unit, and that the control input of the decoding unit is coupled to control inputs of the signal separation unit and the control unit, that the signal separation unit is adapted for the Recording carrier 25 separates the read signal from the packets containing the first information signal and for presenting these packets to the first output, for separating the packets containing the conscious audio signal under the influence of the first control signal fed to its control input, and for presenting these packets at its second output, is arranged for separating the reference signal and the additional packets from the signal read from the record carrier and for adding them to its third output, that the control unit is adapted for the influence of the first control signal deriving from the additional packets the time information 35 associated with the audio signal in question and is arranged for generating the second control signal from its 8601132 PHN 11.753 output from the derived time information and by means of the clock signal of the clock signal generator, and that the video decoder is ingeric it is for decoding the first information signal into an image signal and is arranged to apply this image signal to its output under the influence of the second control signal.

The invention will be explained in more detail with reference to a number of embodiments in the figure description below. Figure 1 shows a “slide show11 with an accompanying text that can be spoken in two languages, figure 2 a record carrier, figure 3 a number of consecutive packages in the information flow, figure 4 the layout of a package, figure 5 the time information associated with the two languages, Figure 6 a device for recording, and Figure 7 a device for displaying images and associated text.

Figure 1 shows very diagrammatically a "slide show", in which a spoken text is supplemented with images. In figure 1a an audio signal in the form of a spoken text is indicated very schematically by means of the line e lying along the time axis t, in a compact language, for example, English. Figure 1b shows the same text very schematically by means of the line f ^, but now spoken in a more flowery language, for instance French. The text pronounced in English is therefore shorter, from t = 0 to t = t4e, than the text pronounced in French. The latter text lasts from t = 0 to t = t4f, where t4f> t4e, as shown in figure 1.

The texts e ^, f ^ can contain one sentence or a number of sentences. The following text is schematically indicated with e2, ^ 2, which starts at the time tg and tgf, respectively. In order for the text pronounced in the two languages to be somewhat synchronous with respect to one another, for example, tge will be taken approximately equal to tg ^.

35 The text e ^ and f ^, respectively, expressed in English and French are illuminated with three images B1f B2 and B ^. Due to the differences in compactness and floweryness 8601182 PHN 11.753 11 of the two languages, images for the two languages will not be offered at the same times. It is clear from figure 1 that the images are presented before hearing the text in the English language rather than the text in the French language, because t1e <t1ff t? E <t2f and 5 t3e <* 3ί ·

When recording the image signals of the three images and the two audio signals associated with the English and French text on the record carrier (compact disc), extra information will have to be added to ensure that the images 10 are correctly displayed during playback. moments are presented with the text pronounced in one of the languages.

Figure 2 schematically shows the record carrier (compact disc). The track 1 spirals from the inside outwards over the record carrier 2 and is also inscribed and read out from the inside out. The first spiral section 3 between points a and b is the lead-in area. This run-in section includes information about the contents of the record carrier. The portion 4 of the track between points b and c contains packets of encoded audio signals, packets of coded image signals, 20 packets of computer data and additional packets. These additional packages may optionally be the same as the packages containing computer data. The spiral part between points c and d is the lead-out area. If the read-out means (the laser beam) end up in this run-out section, the reproduction and the excitation of the motor for running the record carrier are ended.

Figure 3 schematically shows the contents of the track in Figure 2 between points g and h. The part has been chosen in such a way that it contains the (coded) picture and audio information of the 30 pictures and the text of figure 1 spoken in the English and French language. The first package 6 in the part between the points j and k Figure 2 is an additional package composed of a package header 6.1 and a data field 6.2. The package header 6.1 is divided into a first part 6.h, also called "header" and a second part 6.s, also called "subheader *. The following packets 7, 8 ... etc. are similarly divided into a packet header containing a "header" and a "subheader", and a data field. The structure of a package is also o o 0 i 1 8 2

1 4> A

PHN 11.753 12 elaborated in figure 4. A packet, for example packet 8 comprises a total of 2352 bytes and is divided into a packet header 8.1 consisting of 24 bytes and a data field 8.2 consisting of 2328 bytes.

The packet header 8.1 is further divided into a synchronization field S of 12 bytes and a first auxiliary field EH of 4 bytes which together form the header 8.h, and a second auxiliary field TH of 8 bytes which forms the subheader. The synchronization field S indicates the start of a packet. It includes one byte consisting only of “0” bits, followed by 10 bytes consisting exclusively of “1” bits and finally 10 again one byte consisting exclusively of “0” bits. The bytes in the first auxiliary field EH indicate the rank number of the packet in the track. The second auxiliary field TH indicates whether the package is a video package, an audio package or a computer data package. It should be noted that a total of approximately 324,000 (= 72 x 60 x 75) packages are mounted on a compact disc 15. This is because a compact disc contains approximately 72 minutes of music, for which 75 packages must be read per second.

The data field D is divided into data slots DS. For an audio pack, these data slots are selected so that one of them can accommodate one 16-bit audio word of a digital audio signal. For a video packet, these data slots are selected such that one 8-bit video word of a digital video signal can be accommodated in each one. These data slots also have a length of one byte for computer data packets.

As already indicated above, each image is divided into a matrix of 280 x 384 image elements A (i, k).

Where i (= 1, 2, ... 280) is the rank number of the line and k (= 1, 2, ... 384) is the rank number of the picture element on that line (column). If an eight-bit video word Q (i, k) is now transferred for each picture element A (i, k), the transfer of a whole picture requires approximately 47 video packets.

If a packet data field is filled with information words of an audio signal recorded with the quality of the Compact Disc Digital Audio system, 75 audio packets contain information for about one second of music. This is because, as mentioned before, the record carrier is read at a speed of 75 packets per second.

As an audio signal with a lower sound quality 53 0 1 1 8.2 <Λ ΡΗΝ 11,753 13 is recorded on the record carrier after time compression and encoding, fewer audio packages are required to realize one second of music (audio signal) after reading out, decoding and time expansion. It is therefore possible that, after reading out an audio package and after converting the information in this audio package into an audio signal, an audio signal is displayed for a long time interval, for example, where a (video) image has to be made visible somewhere halfway through this time interval. .

Firstly, therefore, it must be taken into account during recording on the record carrier that at the moment that a video image has to be made visible during the reading during the above-mentioned time interval, all information required for this video image has already been read out from the record carrier before this time. and is ready to be displayed on a screen when a control signal occurs.

Second, one must provide information at which time an image should be made visible within the above time interval. It is not sufficient to store only a control signal in the packet head of the relevant audio packet within whose time interval (after time expansion of the information read out from the audio packet) an image falls. Namely, the image should not be made visible at the time of reading this control signal from the audio package, but later, somewhere halfway the said time interval.

Thus, on the one hand, a control signal, hereinafter referred to as a reference signal, and on the other hand, time information must be stored in the record carrier, wherein the time information then indicates at which moment, after a reference signal has been detected during the reading, an image must be made visible.

This time information can be included in one or more of the additional packages. This means that such an additional package contains a table containing the time intervals between the moment of detection of the reference signal and the moment of visualization of an image, and that for the different languages. This table can then for instance be included in the data field of an additional package.

Figure 5 shows such a table, based on the 3 3 U 1 1 3 2 PHN 11.753 14 example of figure 1. It is assumed that during reading the reference signal for the two languages at the same time, namely at time t = 0 in the example of figure 1 is detected. This does not necessarily have to be the case, as will be seen below.

The reference signal may, for example, be included in the packet header (the subheader) of an additional packet. In this case, the reference signal is detected after the conscious additional packet has been read. This detection then takes place at the same time for all languages.

Another possibility is to store the reference signal in the packet header (subheader) of the first packet following the additional packet, which contains information words of the conscious language (the conscious audio signal) in its data field. This means that for each language an associated reference signal is stored in the packet header of the first packet that occurs in the data stream after the additional packet and contains information of the language in question. In this case, the detection for the different languages takes place at different times.

The reference signal may, for example, be stored in a subheader as a codeword with a certain configuration of "ones" and "zeros". After reading this code word (s) can be detected by a suitable detector.

Figure 6 shows an exemplary embodiment of the device 25 for recording an image signal and an associated audio signal.

The device includes a first input terminal 11 for receiving an image (or video) signal, a second input terminal 12 for receiving an audio signal, and a third input terminal 13 for supplying data. The device comprises an encoding unit 23, which consists of a number of parts, namely: an audio encoding unit 14, a video encoding unit 15, a data encoding unit 16 and a signal combining unit 17.

The audio encoder 14 is arranged to encode at least two audio signals (belonging to the at least two languages) and to place these encoded signals in the packets. The audio coding unit 14 shows two coding units 14 'and 14 "connected in parallel. The coding unit 14' is supplied with the audio signal corresponding to the text in the English language via the t * * 'Λ jt.-1 Λ doiiol PHN 11.753 15 input. and encoded in the encoder 14 '. The encoder 14 "is supplied via the sub-input 12" with the audio signal corresponding to the text in the French language and encoded in the encoder 14 ". The audio packages offered by the coding units 14 'and 14 "to the inputs 18 and 19 of the signal combining unit 17 are sequentially arranged by this signal combining unit and are serially presented to the output 20.

10 The coding units 14 'and 14 "insert in the subheader (packet header) of each audio packet that they present at their output, a signal code indicating which of the two audio signals (according to the English or French text) the packets belong to. This means that the encoder 14 'accommodates one signal code corresponding to the one audio signal (English!) in the subheaders of all the packets delivered by the unit 14', and that the encoder 14 "the other signal code, corresponding to the other audio signal (French ) in the subheaders of all the packets issued by the unit 14 ".

20 Instead of the audio coding unit 14 having two parallel coding units 14 'and 14 ", it is also possible that the audio coding unit 14 consists of only one coding unit. There is then only one input terminal 12, instead of the partial inputs 12' and 12" . The audio signals of the two languages must then be applied multiplexed to the input terminal 12 in time. The audio encoder 14 must then, of course, be able to separate the time-multiplexed signals, encode them separately and store them in packets. Furthermore, the audio encoder 14 must then be able to store the correct one of the two signal codes in the subheader of a packet 30. The audio encoder 14 now combines the data packets into a serial data stream which is now supplied via a signal line to the signal combining unit 17.

The video unit is arranged to encode the video signals applied to the input terminal 11 and to accommodate the encoded information in video packets, which are then fed via the input 21 to the signal combining unit 17.

The data is supplied to the 8501132, i via the input terminal 13-. PHN 11.753 16 data encoding unit 16 which encodes the data and arranges it in data packets and presents these data packets at the input 22 of the signal combining unit 17.

The signal combining unit 17 inserts the audio packets, 5 video packets and data packets in sequence. Subsequent packets are then obtained at the output 20, as is indicated, for example, in Figure 3, the packet 6 being, for example, a data packet. The packages 7 and 8 are, for example, audio packages, the package 7 then being the audio signal corresponding to (part of) the English text of Figure 1 and the package 8 being the audio signal corresponding to (part of) the French text of Figure 1 . The package 9 may, for example, be a video package. The data presented through the input terminal 13, which data is encoded by the encoding unit 16 and is contained in data packets, contains, inter alia, the aforementioned time information (see Figure 5). This time information is thus also encoded by the encoding unit 16 and placed in one or more data packets. The time information will preferably be included in the data field of a data packet, so for example the data field 6.2 of the data packet 6.

The device of figure 6 contains a reference signal generator 25, which is supplied with a control signal via a control input 26 and, depending on this control signal, supplies a reference signal which then for the two languages in the subheader of a data packet, in the example thus the data packet 6, 25 can be stored.

The control signal can be supplied externally or can be supplied by a central control unit of the device (not shown), which also takes care of the control of the various units in the device and the timing of the various actions to be carried out in the design.

The reference signal generator 25 supplies the reference signal via the input 27 to the signal combining unit 17, which accommodates the reference signal in the subheader of a data packet presented by the data encoding unit 16 to the signal combining unit 17. Of course, it would also have been possible to supply the reference signals from the reference signal generator 25 to the encoding unit 16. In that case, the encoder 16 8301132 PHN 11.753 17 places the reference signals in the subheaders of the data packets. If the device stores the reference signals in the subheaders of the audio packets, the signal combining unit 17 is arranged to accommodate the reference signals supplied by the generator 25 in the subheaders of the first audio packet of each language following the data packet. For the English language, the reference signal is then stored in the package 7 and for the French language in the package 8.

The data stream containing data, audio and video packets 10 delivered by the signal combining unit 17 to the output 20 are finally presented to the writing unit 28 and written to the record carrier by the writing unit 28 in a manner known to the compact disc.

Figure 7 shows a device for displaying an image signal and an associated audio signal. The device comprises a read-out unit 30 which reads out the information from the record carrier in a manner known to a compact disc and subsequently presents it to the input terminal 31 of a decoding unit 32. The decoding unit 32 contains a signal separating unit 33 which presents the audio packets from the input 34 derives and supplies information stream to its output 35, which derives the video packets from this information stream and presents them to its output 36 and which derives the data packets and supplies them to the output 37. A first control signal is applied to a control input 38. This first control signal can be supplied externally by the user of the device. The user can thus pass on the choice to the decoding unit 32 (via the control input 39) in which language the text of figure 1 is presented to him. Under the influence of this control signal, the separating unit 33 selects only those audio packets containing the audio signal of the chosen language and supplies these audio packets to its output 35.

The output 35 is coupled to an input 40 of an audio decoder 41, an output 42 of which is coupled to an output terminal 43 of the decoder 32. The audio decoder 41 encodes the audio packets in a manner inverse to the encoding by the audio encoder 14 (Figure 6i ), so that an analog audio signal is produced at the output 42 in accordance with the passage in the relevant language, see figure 1. This audio signal is made audible to the user by means of the loudspeaker 44 connected to the output terminal 43.

8 δ 0 11 3 ‘PHN 11,753 18

The output 36 is coupled to an input 45 of a video decoder 46, an output 47 of which is coupled to an output terminal 48 of the decoder 32. The video decoder encodes the video packets in a manner inverse to the encoding by the video encoder 15. Is a whole image, such as image of Figure 1, decoded by the video decoder 46, the image information of this image is stored in a memory in the decoder. At the time of the occurrence of a second control signal which is applied to the control input 49 of the video decoder 46, this image is read from the memory and is presented via the output 47 to a screen 50 connected to the output terminal 48.

The data packets are supplied by the separating unit 33 via the output 37 to the input 51 of a control unit 52.

The data packets are decoded therein so that they can be used in unit 52 in order to be able to control some program steps in the device. The control unit 52 is also arranged for reading out the time information from a data field (such as 6.2 in figure 3) of a data packet, such as the data packet 6 in figure 3. In addition, the first control signal 20 is applied to a control input 53 of the control unit 52. The control input 53 is therefore coupled to the control input 39 of the decoding unit 32.

Under the influence of this first control signal, indicating the choice of the language in which a text is displayed, the control unit 52 only reads out that time information corresponding to the selected language. If the language English was chosen, the controller 52 would only read the information in the top row (indicated by "e") in the table of Figure 5.

The control unit has an output 54 to which the second control signal is output for supplying the control input 49 of the video signal decoding unit 46.

The derivation of this control signal is explained below: first for the number that the reference signals are included in the subheaders of data packets, and then in case the reference signals for each language are separately included in a subheader of an audio packet.

Is a reference signal included in the subheader of a data packet that is the control unit 52 adapted for deriving a data packet presented at its input 51 from 8801182 PHN 11.753 19 (in particular from the subheader of that data packet, such as the data packet 6 in figure 3) and detecting the reference signal. The control unit 52 is then furthermore adapted to measure the time intervals t1e, t2e and tge and t ^, t2f, t ^ (see figure 5) after the detection of the reference signal, depending on which language has been chosen, and for supplying of a second control signal at the moments when these time intervals have expired. This means that the video decoder 46 upon the reception of the three second control signals via the input 49, the three images, B2 and B3 from the image memory belonging to the decoder 46 (not shown), are fed to the monitor 50 and then at the times t1e. (or t1f), t2e (or t2f) and t3c (or t3f - depending on the chosen language) are made visible.

Thus, it has been assumed in the foregoing that the control unit 52 detected the reference signal from the subheader of the data packet 6 at the instant t = 0 from Figure 1.

The time intervals are measured by the control unit 52 using a clock signal supplied by the clock signal generator 55 via the input 56 to the control unit 52.

If, however, a reference signal is included in the subheader of an audio package, the deriving of the second control signal by the control unit 52 takes place in a different manner. The detection of the reference signal must now take place either in the signal separating unit 33 or in the audio decoding unit 41. The most obvious is to carry out the detection in the decoding unit 41, since this decoding unit 41 is offered only those audio packages containing the audio signal in the chosen language. This means that there is * an additional coupling of the detection device in the decoding unit 41 via the output 57 to a control input 58 of the control unit 52 for supplying a control signal to the control unit 52 at the moment of detection of the reference signal in the subheader of an audio package (which is the package 7 for the English language, and the package 8 for the French language). The coupling between the output 57 of the decoding unit 41 and the control input 58 of the control unit 52 is indicated by a broken line. The 6ü 1 1 3 2 i -Λ PHN 11.753 20 control unit 52 then counts the time intervals t ^ e (or t ^), t2e (or t2f) and t3 (or t3f - depending on receipt of the detection signal via input 58). the selected language), using the clock signal from the generator 55, and supplies the second control signal via the input 49 to the video decoder 46 at the aforementioned 5 times, so that the images Bj, B2 and B3 are displayed on the screen 50 at these times. be made visible.

Thus, the operation during reading is such that the information transfer is controlled by control signals contained in the audio information. The reading of the audio information takes place undisturbed and more or less continuously. This means that audio blocks read from the record carrier and subsequently decoded to audio signals are presented directly to the loudspeaker 44. However, the transmission of the video information to the screen 50 is controlled by the control signals present in the audio information.

It is further possible to repeat the time information, the table of figure 5 or a part thereof, and also to store it in a later data package (additional package), for example the additional package i in figure 3, being the next additional package in the information flow after the package 6. Saving this again (part of the time information in a later additional package has the following reason.

For example, it may be that the total information content of the passage in Figure 1, in both languages and together with the information content of the three images, is more than in packages 7, 8 through i-1. can be saved. This means that information required for the passage in Figure 1 is also stored in the packets j, k, 1, ...

If it is desired to make a "random access" to the information on the record carrier, it is the case that reading can start with the data packet 6 or with the data packet i. For example, suppose that during the reading of the audio packets that follow the data packet i, the image B3 of figure 1 still has to be made visible on the screen 35, while the readout only takes place from the data packet i. Then, in the data packet i, at least the time information associated with the picture B3, i.e. at least the right column of the table of figure 5, must be stored in the data packet i.

It is to be noted that the invention is not limited to the exemplary embodiments as described above. Various modifications to the described exemplary embodiments are possible without departing from what is within the scope of the invention, as defined by the claims.

It should also be noted that other features related to the interactive application of compact disc (CD-I) are described in the following previously filed Dutch patent applications: NL-TV 86.00.450 (PHQ 86.003), NL-TV 86.00.980 (PHN 11.734), NL-TV 86.01.005 (PHN 11.738) and in British patent application ............... (PHB 33.255), all of the applicant.

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Claims (14)

1. Method for recording and / or reproducing an image signal and an associated audio signal in a record carrier, respectively, wherein during recording the image signal and the audio signal are encoded into a first and a second information signal, respectively, containing information words which are arranged in packets (frames), each packet is provided with a packet header (header) and a data field, in which a data field of a packet contains a number of information words of the image signal or the audio signal, the packet header indicates the information signal to which the information words in the data field belong, after which the packages are registered on the record carrier; and wherein, during playback, the packets are read from the record carrier and decoded to obtain the image signal and the associated audio signal, characterized in that, for recording at least a second audio signal associated with the J image signal, the second audio signal encoded to a third information signal containing information words contained in packets, which in the packet header of those packets containing an encoded audio signal is additionally indicated to which of the two or more audio signals the information words in a data field of a packet belong, that further reference signals and additional packets are recorded in the record carrier, which additional packets for each of the two or more audio signals associated with an image signal contain time information about the time between the moment of detection of a reference signal after reading and the moment at which a n read out image signal must be made visible on a screen, and during playback the reference signals and the additional packets are read from the record carrier, under the influence of a first control signal the time information associated with one of the audio signals is derived from an additional packet and subsequently from the time information thus derived and a detected reference signal, a second control signal is derived for displaying an read-out image signal on a screen, and that under the influence of the first control signal only the one aforementioned audio signal is reproduced. 2. Method according to claim 1, characterized in that the reference signal is stored in the packet header (subheader) of a 1 C v 3J £ 3? 1 £ p. · J «r & w 5 * -yr • *„ PHN 11.753 23 additional package. Method according to claim 1, characterized in that for each audio signal an associated reference signal is stored in the packet header (subheader) of the first packet following the additional packet 5, which contains information words of the conscious audio signal in its data field. Method according to one of the preceding claims, characterized in that the time information is recorded in the data field of an additional packet. 5. Device for recording an image signal and an associated audio signal in a record carrier, for carrying out the method according to any one of claims 1 to 4, comprising - a first input terminal for receiving the image signal, 15. a second input terminal for receiving the audio signal, - an encoding unit with a first and a second input coupled to the first and second input terminal and an output terminal, respectively, which encoding unit is adapted to encode the image signal and the audio signal into the first and second information signal, respectively, in The form of consecutive information words, is arranged for accommodating the information words in packets (frames), is arranged for accommodating a signal code in the packet header indicating the information signal to which the information words belong in the data field of the associated packet, and is arranged for the delivery of overlapping vo Next packets at its output, - a write-in unit, with an input coupled to the output of the encoding unit, which write-in unit is arranged for writing the successive packets in the record carrier, characterized in that the coding unit is arranged for encoding at least a second audio signal associated with the image signal into a third information signal in the form of consecutive information words, arranged for accommodating these information words in packets, arranged for accommodating a signal code in the packet header of packets which contain an encoded audio signal, indicating to which of the two or more audio signals the information words in the data fields of these packets belong, 8 3 0 1 1 3 2 PHN 11.753 24 that the encoder contains a reference signal generator, for supplying reference signals, that the unit is further arranged for generating additional package which additional packets for each of the two or more audio signals associated with an image signal contain said time information, and is arranged to supply these additional packets to its output terminal. 6. Device as claimed in claim 5, characterized in that the encoding unit comprises - an audio encoding unit for encoding an audio signal, with an input coupled to the second input terminal, and an output, - a video encoding unit for encoding an image signal, with an input coupled to the first input terminal, and an output, - a signal combining unit having a first, a second and a third input coupled to the outputs of the audio encoder 15 and the video encoder, respectively, the reference signal generator, and an output coupled to the output terminal, which encoder further includes a third input terminal for receiving said time information, which third input terminal is coupled to a fourth input of the signal combination unit, and that the signal combination unit is arranged for storing the information words of the audio encoder and the video encoder in the data fields of packages, is furnished v For accommodating the signal code in the packet header of packets, and is arranged to store the time information in the additional packets. Device according to claim 6, for carrying out the method according to claim 2, characterized in that the signal combining unit is arranged for storing the reference signal in the packet header of an additional packet. Device according to claim 6, for carrying out the method according to claim 3, characterized in that the signal combining unit is arranged for storing, for each audio signal, a reference signal associated with the audio signal in the packet header of the first following the additional packet packet containing information words of the conscious audio signal in its data field. 9. Device as claimed in claim 6, for carrying out the method as claimed in claim 4, characterized in that the signal combination unit is adapted for recording the time information in the data field of an additional package. 10. Device for reproducing an image signal and an associated audio signal from a record carrier, for performing the method according to any one of claims 1 to 4, comprising - a reading unit, for reading consecutive packets from the record carrier and for supplying these packets to an output, a decoder with an input coupled to the output of the reader, and a first and second output, which decoder is adapted to separate packets containing information words from the first information signal and of packets containing information words of the second information signal, is arranged to decode the first and the second information signal into the image signal and the audio signal, respectively, and is arranged to supply these signals to a first and second output terminal, respectively, characterized in that the decoder contains a control input v for receiving the first control signal, and that the decoding unit is arranged to derive one of the two or more audio signals under the influence of the first control signal and to supply this audio signal to its second output terminal, that the decoding unit is further arranged for separating the reference signals and the additional packets from the information read from the record carrier, for deriving the time information associated with the conscious audio signal under the influence of the first control signal, for deriving the second control signal, and for supplying the image signal at its first output terminal under the influence of this second control signal. 11. Device as claimed in claim 10, characterized in that the encoding unit comprises a signal separating unit, an audio decoding unit, a video decoding unit, a control unit and a clock signal generator 35, the input terminal of which is coupled to an input of the signal separating unit, a first, a second and a third output of which is coupled to inputs of the video decoder 8001132 PHN 11.753 26 and the audio decoder respectively a first input of the control unit, outputs of the video decoder and the audio decoder are coupled to the first and second output terminal, an output of the clock signal generator is coupled to a second input of the control unit, an output of which is coupled to a control input of the video decoding unit, and that the control input of the decoding unit is coupled to control inputs of the signal separation unit and the control unit, that the signal separation unit is arranged for separating the packet containing the first information signal from the record carrier 10 and for presenting these packets to the first output, for separating the packets containing the relevant audio signal under the influence of the first control signal fed to its control input. and for presenting these packets to its second output, it is arranged for separating the reference signal and the additional packets from the signal read from the record carrier and for adding them to its third output, that the control unit is arranged for the influence of the first control signal from the additional packets deriving the time information 20 associated with the conscious audio signal and is arranged for generating the second control signal at its output from the derived time information and with the aid of the clock signal from the clock signal generator, and that the video decoder is arranged to decode the first information signal into an image signal and is arranged to apply this image signal to its output under the influence of the second control signal. 12. Device according to claim 11, for carrying out the method according to claim 2, characterized in that the control unit is adapted to separate the reference signal from the packet head of an additional packet. 13. Device as claimed in claim 11, for carrying out the method according to claim 4, characterized in that the control unit is adapted to separate the time information 35 associated with the relevant object from a data field of an additional packet under the influence of the first control signal. audio signal. Record carrier obtained according to the method according to any one of claims 1 to 4, characterized in that in the record 0 * *: iv PHN 11.753 27 record carrier information words of at least three information signals are included in the data fields of data packets, wherein a data field of a packet of information words of only one of the three or more information signals is included, that the record carrier additionally contains reference signals and additional packets, which additional packets contain the time information. 8301182